You will need Paint Shop Pro 9, which you can get from Jasc  for 30 days trial.
Download the daffodil outline here.

Open the outline you downloaded.

Click inside of any of the petals and expand it to 3. Flood fill it with color #c19a17.

Click on airbrush. Change the color to #ba660a. Airbrush settings below.

Presets=default
shape=round
size=20
hardness=10
step =1
density=15
thickness=100
rotation=0
opacity=100
blend mode=normal
rate=0

Airbrush around the petal as shown below.

Add a new raster layer. Click on Smudge Tool. Settings below.

Presets=default
shape = round
size=16
hardness=10
step=1
density=50
thickness=100
opacity=100

Smudge the image as shown below.

New raster layer. Click on Airbrush tool/change the color to #9f3f00. Apply airbrush around the edges of the petal as shown below. Then slightly smudge it to soften it. Merge layers visible.

Click on paintbrush. Change the color to #dabc9a. Settings below.

presets=default
shape=round
size=3
head loading=69
viscosity=100
firmness=4
bristle size=10
auto clean checked.

Add a new raster layer. Paint a line on the center of the petal. Convert to raster layer. Click on Adjust/Blur/Gaussian blur to 1.50. Merge the layers visible. See image below.

DESELECT.

Do the same process to the rest of the petals. Don not forget to convert the layers to raster and definitely always merge all the layers visible.

Your image should look similar to the image below after you get all the petals done.

I will leave you finish the rest. By now you should have an idea of how to use the smudge tool. Just a little adjustments on sizes and colors and a little bit of patience should help you get the rest of the flowers done. I would like to know how it turned out. Email me the result. Thanks. :)